[FFmpeg-devel] flashsv error due to negative linesize value - not an intentional cross post!
Wed May 9 21:45:22 CEST 2007
To get even more specific, it is this line:
dptr[j] = nsptr[j];
in copy_region_enc that is failing, and it is happening at the ends of
the row / column runs.
In short, I really need more info on the meaning of linesize being
negative. I've dug through the past mail archive and found:
> It's up to your program to pack it in an acceptable fashion. linesize
> can be absolutely anything; it has nothing to do with the width of the
> picture. In fact it can be negative if the decoder stores the picture
> upside-down, iirc.
> its not meaningless, the image can be flipped and data can point to
> the last line
Ahh, this may be the key.
So, if linesize is negative, then data will point to the end of the
buffer for plane ? or will it point to the beginning of the first
line of the last row?
Here's another way to put it: is
data[linesize * row + column]
always valid even with a negative linesize, assuming a positive row
and column value?
Just trying to get the fine details down here so I can get this fixed.
I'm getting close.
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